The military uses various devices in a number of different environments and for a number of different purposes. Military devices which include an electric battery are often used in an unpredictable and unforeseeable manner and in locations where external electrical power is not readily accessible. Military devices which include an electric battery include armed and unarmed transportation vehicles, artillery devices, and other devices carried in the field by military personnel. Extra batteries may be carried in support of such military devices due to the limited energy content of electric batteries and the length of time needed to recharge electric batteries. The weight and volume of the extra batteries may impair the mobility of military devices and personnel as well as adding higher cost and disposal problems. While an increased battery energy density would reduce the weight and volume of the extra batteries, unfortunately, the availability of batteries with increased energy density is only slowly increasing. In non-military applications, extra batteries may be purchased to avoid an inconveniently long time to recharge.